After wearing a cap for 15 years and then removing it, its really irrelevant what is or isn't underneath it, be it your own hair, a wig or even a cat!
The difference people will notice is that you're not wearing your hat/cap.
They won't be judging your hair because they have nothing but the hat to compare it with.
But if you have a head of hair that looks good, the ONLY reaction you will get will be compliments.
You won't want to wear the hat and you'll feel like a whole new world has opened up to you.

I speak from experience.
I wore a baseball cap for 2 years, during transplants and trying out wig wearing.
Just like you, I thought I would gradually segway from hat wearing to exposing my new hair.
In reality it was such a relief to not be wearing the hat, I abandoned it much sooner than planned.
I wish you all the best and hope it works out well for you.